A vehicle battery is to be understood in particular as those batteries that, in hybrid or electric vehicles, have the function of supplying electrical energy to the drive train. Such vehicle batteries are standardly diagnosed in a workshop using a testing device, for example a diagnostic tester. Diagnostic testers are often fashioned generally for the diagnosis of vehicles. The connection of the testing device to the vehicle battery frequently takes place via a standardized on-board diagnostic (OBD) interface realized in the vehicle. Such a standard can for example be the OBD-I, OBD-II, OBD-1.5, or the EOBD standard.
In hybrid and electric vehicles, in case of error it is often necessary to remove the vehicle battery, for example a high-voltage battery. This removed vehicle battery has to be further tested or diagnosed with regard to its functionality in the state in which it is removed from the vehicle. The existing diagnostic infrastructure, in particular the testing device, can, generally, longer be used for the removed vehicle battery in the workshop, because the vehicle battery itself no longer has the on-board diagnostic interface.
PCT Published Application No. WO/2009 011875 A2 describes a method and a device for testing an electric vehicle. The device has a data bus connector that is capable of being connected to a data bus of the electric vehicle. The data bus can also be an OBD data bus. The device has in addition a microprocessor that can read out, via the data bus, voltage and current information about the data bus of the electric vehicle, and can diagnose the operation of the vehicle based on the read-out current and voltage information.